Phonograph



Sept. 29, 1942. E. L. TRIMAN :TAL 2,297,085

P HONOGRAPH Filed July 14, 1941 a sheets-sheet 1 VII Il Illlllllll Sept29, l942- E. L. TRIMAN ETAL 1 2,297,035

PHONOGRAPH Y Filed July 14, 1941 8 Sheets-Sheet 2 SePt- 29, 1942- E. L.TRIMAN E'TAL 2,297,085

PHONOGRAPH Filed July 14, 1941 8 Sheets-Sheet 3 #77 rp /////m|\\\\\ w 'W/Mww/ Lug/06 sePt 29 1942. E. L. TlMAN Er AL 2,297,085

PHONOGRAPH Filed July 14, 1941 8 Sheets-Sheet 4 PHONOGRAPH Filed July14, 1941 8 Sheets-Sheet 5 17a/em ifi f?. Qye/Le L.

Sept. 29, 1942.

E. l... TRIMAN ETAL PHONOGRAPH Filed July 14, 1941 a sheets-sheet 6 E.L. TRIMAN ETAL sept. 29, 1942. j

PHONOGRAPH Filed July 14. 1941 8 Sheets-Sheet 7 linde/dara Zuge/e LWiliam Sept. 29, 1942. E. L. TRIMAN ETAL Paonosmrn Filed July 14. 1941 8Sheets-Sheet 8 Patented Sept. 29, 1942 PHONOGRAPH Eugene L. Triman andLawrence E. Dettle, Chicago, Ill., assignors toRock-Ola ManufacturingCorporation, Chicago, Ill., a corporation.

of Delaware Application July 14 1941, Serial No. 402,310

27 Claims.

Our invention relates to phonographs, and more particularly to acoin-controlled phonograph system comprising a central station and aplurality of subscribers stations.

Heretofore automatic phonographs were limited to the playing of arelativelysmall number of selections now available on automatic phono-.l

graphs is considerably greater than it has been in the past, it would bedesirable if a still larger number of phonograph records were availableor if it were possible to provide an extensive repertoire of selectionsor a library of phonograph records.

This would be possible if a phonograph system were provided whereby alibrary of phonograph records were available at a central station whichwould serve a number ofV subscribers stations. It furthermore would bedesirable if such a system could be provided for use in conjunction withthe present automatic phonographs.

It is, therefore, an object of our invention to provide an improvedsystem for` electrically reproducing phonograph records.

.Still another object of vour invention is to provide a phonographsystem having a new and improved coin-controlled circuit arrangement fortransmitting impulses from a subscriber station to acentral station, theimpulses corresponding to the value of the coins received at thesubscriber station. a

Still another object of our invention is .to provide an improvedphonograph system having a circuit arranged for receiving and indicatingimpulses at the central station.

Still another object of our invention is to provide an improvedphonograph system for electrically reproducing phonograph records whichis provided with coin-controlled means yfor controlling the eiectivenessof one of the elements of the apparatus for reproducing phonograph.

A still iurtherfobject of our invention is to provide animproved'phonograph system for electrically reproducing phonographrecords which may be utilized in conjunction with the present automaticphonographs,

Other and 'further objects of our invention will become more readilyapparent from Athe following description taken in connection with ytheaccompanying drawings in which:

Fig. 1 isl a'circuit arrangement for electrically reproducing phonographrecords in'accordance with our invention, andwhich comprises a singlechannel system as utilized between one subscriber and the centralstation;

Fig. 2 illustrates the arrangement of said equipment at the centralstation;

Fig. 3 and Fig. 4 are front and top views respectively of the subscriberplay indicator located at the central station;

Fig. 5 illustrates a detail of the control and signal circuits Vlocatedat the central station;

Fig. 6 and Fig. 7 illustrate the arrangement and operation of certainswitches controlled by the member oi the phonograph pick-up;

Fig. 8 is a View showing certain mechanical details of the switchactuating means shown in Figs. 6 and 7;

Fig. 9 is a perspective view showing means for maintaining thephonograph pick-up in a'position of rest;

Fig. 10 illustrates another switch arrangement which may be actuated bythe phonograph pick- Fig. 11 and Fig. 12 illustrate certain details ofthe apparatus shown in Fig. 10;

Figs. v13 to 16 illustrate the operation of the switch actuating meansshown in Fig. 10; and

Fig. 17 shows a circuit arrangement embodying our invention as appliedto a double channel system.

' Referring more particularly to Fig. 1, there is shown therein thecircuit arrangement utilized between each subscriber station and thecentral station and Which is termed a single channel system. A singlepair of telephone lines interconnects the subscriber .with the centralstation. Since it would be desirable to provide a larger number/ofavailable phonograph records, particularly in conjunction with existingautomatic phonographs, certain elements shown in Fig. 1 have beenenclosed within dotted lines to indicate that these elements maycomprise elements commonly found in existing automatic phonographs.Thus, a phonograph oi the automatic type is provided with a phonographturntable and motor 2| which cooperates with a phonograph pick-up 22,illustrated herein as being of the piezo crystal type, which isconnected through a suitable control network comprising the resistors23, 24 and 25 to an amplifier 26 which in turn is connected to the soundreproducer 21. The connection between the resistors 23 and 24 is openedso as to permit the insertion of a singlepole double throw switch 28which, when thrown to the right-hand position, places the phonographreproducing apparatus in operation for normal operation as an automaticphonograph exclusively. The switch 28 fis Ymechanically connected to aswitch 29 which is also a single-pole double throw switch and which isconnected between a coin chute or switch 3| and an accumulator 32 whichis connected to be energized from a transformer 33 which in turn isconnectedtoa suitable source of power 34. When the switch 29 is thrownto the right, the coin chute or switch 3| operates to actuate theaccumulator magnet 32 a number of times corresponding Vto the value ofthe coin or coins received by the coin chute or switch 3|. Thisaccumulator and the automatic phonograph may be of the type shown andillustrated in the United States Letters Patent No. 2,159,834 grantedMay 23, 1939, upon the application of Paul H. Smyth, Jr., and which isassigned to the same assignee as the present application.

When the switches 28 and Y29 are thrown to the left as shown in Fig. 1,the automatic phonograph vis connected to become a part of the systemcomprising our invention whereby'the phonograph is provided with amicrophone 35 which may be connected through a Ysuitable amplifier 3S toa transformer'31, the output of which is normally connected throughswitch contacts 38 and 39 to one side of a transformer 4| which in turnis connected to a telephone line 42 leading to a central station. Theother side vof the output of the transformer 31 is connected through abalancing network comprising a capacitor 43, a resistor 44,an'adjustable'resistor 45, and a pair of contacts 46 to theother side ofthe transformer 4|. By this means the subscriber may communicate withthe operator at the central station. In order to signal the centralstation the subscriber inserts a coin or coins in the coin chute 3|which, in the present instance, as illustrated, is connected between acapacitor V48 and a relay 49. The transformer 33 is'serially connectedto a rectifier v41 which may comprise a pair of vacuum tube rectifierelements o r any other suitable rectifier means; The transformer 33 andthe rectier 41 are connected to a capacitor 48 which is seriallyconnected with the relay 49 so that the rectifier 41, energized frompower received through the transformer 35 operates to supplyuni-directional current to the capacitor 48 thereby to store energythere in to the' serially connected 'capacitor 48 and relay coil 49 inturn are connected through the switch 29 to the coin chute or switch 3|.

Whenever the coin-operated switch 3| is closed by insertion of a coin, acircuit is completed from one side of the capacitor 48 through the relaycoil 49, the switch 29 and.l the coin-operated rswitch 3| to the otherside of the capacitor 48.

The relay coil 49' is provided with a copper disk or slug in a mannersimilar tothe construction used in alternating current relays,V andhenceforth, for convenience, this relay coil 49, the copper slug 5| andthe switches controlled therebynwill be referred to as an alternatingVsuch that the current supplied thereby has a vcurrent relay. Theenergization of the relay coil definite maximum limit. Thus, wheneverthe relay 49 is initially energized, the voltage appearing across thecapacity 48 is initially relatively high because the no-load voltage ofthe rectiviier circuit is also high, yet during further discharge of thecapacitor 48 no large uni-directional current impulses are supplied bythe rectifier 41 because the characteristic of the rectifier circuit tosupply a limited amount of current. The operation of the relay 49causesthe switch contacts 39 and 43 to be broken-and fui-ther causes thecontacts 53 and 54 to be closed thereby connecting alternating currentfrom a transformer 55 energized from a suitable source such as 34, tothe transformer 4i through alternating current filter means 56 and 51which may comprise, as illustrated, choke coils designed to permit lowfrequency alternating current to pass therethrough having a frequencycorresponding `to a frequency supplied by the isolation transformer-55from a source of current 34. Thus, each time that the coin-operatedswitch 3| is closed-by a coin or a plurality of coins orv a number oftimes-corresponding tothe value of a coin, the alternating currentvrelay 49 disconnects the remaining phonograph apparatus :from 'thetelephone line 42 and connects the telephone line 42 throughthe-transformer 4|, through the alternating current filter means 53, 51to the alternating current source 55 thereby to transmit alternatingcurrent impulses to the central station which impulses correspond innumber to the value of the coins inserted in the coin chute or switch 3|Y Whenever alternating current supplied from the transformer 55 isconnected to be transmitted from the subscriber station to the centralstation over the telephone Yline 42 by operation of the relay49,7another relay coil 58 is energized to open the'circuit contacts 38.The coil 5|] is connected to one ofeach oftheY terminalsof thealternating current filter meansV 53 and 51 so as to be energizedwhenever alternating current flows throughV these lter means. Theoperation of the relay 50'in opening the contacts 36 is a featurewhichrpositivel'y insures the disconnection of the sound reproducingapparatus including the sound reproducer 21 from the telephone line 42since the contacts 38 are connected in series with the contacts 39 andone portion of the secondary winding of theY transformer 31. Thus,

apparatus of the subscriber as well as protection for the apparatus. Theisolation transformer 55 is preferably of a one to one ratio so assupply relatively high alternating current potential to the telephoneline 42 whenever a coin impulse is to be transmitted. While this voltageat the subscriber station may be equal to the voltage at the source 34,the telephone line 42 introduces an appreciable voltage drop so that atthe central station the alternating current voltage is considerableless.

Upon signaling the operator by means of the coin-operated switch 3l, thesubscriber cornmunicates with the operator by means of the microphone 35and amplifier 35 to inform the operator what selection or selections aredesired. These selections are placed upon suitable means forelectrically reproducing phonograph records and the energy istransmitted from the central station through the telephone line 42 ltothe subscriber station which is provided with means interconnecting thetelephone line 42 with the sound reproducer 21 and the amplifiertherefor 26. This means comprises the switch 28, a suitable transformer58, an attenuator 59 which is connected between the midpoint of thesecondary winding of the transformer 31 and the juncture between theswitch contacts 45 and the balancing network comprising the capacitor43, the resistor 44 and the adjustable resistor 45.

The balancing network comprising the capacitor 43, the fixed resistor 44and the adjustable resistor 45 serves to permit the circuit to bebalanced so as to prevent howl and feedback. The balancing network is sorelated to the secondary winding of the transformer 31, the attenuator59 and the telephone line 42 so as to form a bridge circuit. When thisbridge circuit is balanced, incoming signals are eiiective across theattenuator 59 so as to be reproduced by the sound reproducer 21. Signalsproduced by the microphone 35 are ineffective across the attenuator 59of the balancing network, and are effectively fed to the telephone line42 by means of the transformer 4I. By proper adjustment of the resistor45 of the balancing network, the operations just described can beobtained thereby eliminating such conditions as would be likely to causehowl or feedback.

At the central station the telephone line 42 is connected to certainapparatus including a transformer 5| whichis connected to acoin impulsedetector circuit comprising a capacitor 62 and a rectifier 63 which isconnected to a reversely arranged rectifier 64, the other terminal ofwhich is connected through a relay coil 65 to the juncture between acapacitor 62 and the rectifier 63. The coin impulse detector circuitcomprising the secondary Winding of the transformer 6|, the capacitor 62and the reversely connected rectiers 63 and 64 is characterized by beingsensitive to alternating current impulses of short durationvirrespective of what portion or portions of alternating current cyclesmight be received. Thus the coin impulse detector circuit is sensitivet0 as little as a half cycle of alternating current and the relay coil65 will be operated thereby to close the contacts 66 which are connectedto supply energy from a suitable source 61 to a subscriber playindicator 68. The alternating current impulses received at the centralstation from the telephone line 42 by means of the transformer 6| arenow at a relatively low voltage, for example from 30 to 20 per cent ofthe original impressed voltage value, yet are relatively high withreference to voltages of normal voice currents. The coin impulsedetector circuit,- while being sensitive to as little as one-half cycleof alternating current, generally is actuated by at least a full cycleof alternating current. Each portion of the full lcycle is rectified,and hence, as will be apparent to those skilled in the art, the circuitarrangement -is such that the effective uni-directional current voltageacross the relay coil 65 is doubled thereby insuring positive operationof the relay. Thus the coin impulse detector circuit in effectdifferentiates quantitatively between signals-of different intensity,the alternating current coin impulse signal being the only signalsreceived which are above the required predetermined level necessary tocause operation of Vthis circuit.

This subscriber play indicator indicates the value of the coin or coinsdeposited by the subscriber at the subscriber station and furthermore isprovided withisignal means for calling the operator. The central stationis provided with a talk-listen switch 69 which has a pair of contacts 1|and 12 normally connected with the switch blades thereof so that thetelephone line 42 is connected through the transformer 6l, and anisolating and current limiting capacitor 13, to the output transformer14 of the phonograph pick-up amplier. The switch blades cooperating withthe contacts 1| and 12 may be actuated by throwing the switch 59 to theleft so as to complete a circuit through switch contacts 15 and 15 whichare connected to a suitable headset or telephone receiver 11 whereby theoperator may hear what is spoken into the microphone 35 at thesubscriber station. The talklisten switch is furthermore provided with apair of normally open switch contacts 18 and 19 which are connectedthrough a suitable amplifier 8| to a microphone 82 by means of which theoperator is connected through a portion of the phonograph pick-upamplifier including the vacuum tube 83 and the output transformer 14,the switch contacts 1i and 12, through the isolating capacitor 13 to atelephone line 42, whereby the telephone operators voice is reproducedthrough the amplifier 26 and the sound reproducer 21 located at thesubscriber station.

The central station is furthermore provided with a phonograph turntableand motor 84 which cooperates with a phonograph pick-up 85 which hasbeen shown as being of a piezo crystal type. The output of thephonograph pick-up 85 is connected through a suitable circuitcomprising'a resistor 86, a parallel connected capacitor 81, a capacitor88 and an adjustable resistor 89 to the control grid of the vacuum tubeamplifier 83. The other side of the phonograph pick-up 85 is connectedto ground and also through a capacitor 9| t0 the other side of theadjustable resistor 89 which in turn is connected to a resistor 92 whichis also connected to ground. The cathode of the vacuum tube 83 may beconnected through a suitable resistor 93 to ground in order that thevacuum tube 83 may be utilized as part of the voice transmission channelfor the central station operator. The output 0f the microphone amplifieris connected through the switch conta-cts 18 and 19 to a resistor 94which is connected through to the control grid of the vacuum tube 83 andthe other side of the amplifier 8| is connected to the cathode of thevacuum tube 83.

Since ytelephone lines have the characteristic of attenuating differentfrequencies by diierent amounts, it is desirable to provide some form ofcompensation sov that the reproduction at the subscriber station will bereasonably faithful and satisfactory. This is accomplished by thecircuit connected between the phonograph pickup 85 and the electrodes ofthe amplifier tube 83. The parallel connected resistor 86 and capacitor81 form a network which provides certaincompensation for the middlerange of frequencies to` be transmitted. The capacitor 88 connectedbetween the movable contact of the adjustable resistor 89 and one endthereof supplies compensation for the high frequency range. Thecapacitor 9| and the resistor 92 provide the necessary degree ofcombination for the lower or base range of frequencies. By means of thisarrangement, the necessary compensation is introduced into the circuitahead of the first amplifying means such as the tube 83 and directly inback of the phonograph pick-up 85.

From the previous description it will be apparent that a central stationoperators voice is received by the microphone 82 and amplified by theamplifier 8| whereupon it is further amplied by the amplifier 83 priorto transmission tion operators voice to be mixed with the music lwhenever a phonograph record is being reproducedby the means of thephonograph turntable 84 and the pick-up 85. In the subscriber stationthe voice of the central station operator is predominant since, by meansof the cathode resistor Y 93, the amplification of the energy receivedfrom the phonograph pick-up 85 is subordinated to the amplification ofthe central station operators Voice currents.

Assuming that the amplifier 83 is transmitting energy from a phonographrecord, and the central station operator wishes to talk to thesubscriber station, the switch 69 is thrown to the right thus causingthe switch contacts 19 to connect the grid of the amplifier tube 83 toground through the resistor 94. This reduces the amplication of thephonograph currents by a predetermined amount. At the same time theswitch contacts 18 connect one side of the amplifier 8| to the cathodeside of the cathode resistor 93 of the vacuum tube 83. Since one side ofthe amplifier 8| is grounded, and the other side of the resistor 93 isgrounded, voice energy of the `central station operator received by themicrophone 82 and amplified by the amplifier 8| is impressed across thecathode resistor of the vacuum tube amplifier 83 thereby causing thecentral station operators voice to predominate over the music receivedat the subscriber station.

While the circuit arrangement shown includes only the apparatus utilizedbetween a single subscriber and the central station, it of course, is tobe understood that any number of similar units may be provided for anydesired number of subscribers. Thus the central station may be providedwith a plurality of units such as has been illustrated in Fig. 2 whereina suitable cabinet 95 houses a plurality of units each comprising arecess 96 for housing a turntable and phonograph pick-up such as 84 and85, a control panel 91 upon which is mounted the talk-listen switch 69,the subscriber play indicator 68 and signal lights 98 and 99, and a'record storage recess |0I. The cabinet 95 is preferably further providedwith a series of record storage units |02 wherein the records arepermanently stored in proper order and classification so as to bereadily available Whenever any subscriber requests a particular record.The record storage recess |0| is utilized to house a number of recordswhenever a subscriber has requested the playing of a plurality ofrecords.

The subscriber play indicator 68, which is mounted on the panel 91 aswill be apparent by reference to Figs 3 and 4, comprises an indicatorwheel |03 having indicia thereon visible through a suitable opening |04in the panel thereof 91. The indicator dial |03 is mounted upon a shaft|05 which is provided with a ratchet wheel |06 which in turn is springbiased by a suitable helical spring |01 so as to tend to turn the shaft|05 in a clockwise direction shown in Fig. 3. The ratchet wheel |06 iscontrolled by an escapement which is controlled by an armature |08actuated by a magnet coil |09. The magnet coil |09 is connected incircuit with a source of energy 61 and the switch contacts 66 of therelay 65 shown in Fig. 1. The armature |08 may be provided with one of apair of contacts I|| which may be connected so as to operate a totalstation play indicator or mechanism. Whenever the relay |09 isenergized, the armature |08 is attracted thereby actuating theescapement |01 so as to permit the shaft |05 to be rotated the distanceequal to one tooth of the ratchet wheel |06. Whenever this occurs,rotation of the shaft removes a stud ||2 mounted on the shaft |85 fromengagement with and out of contact with a switch blade ||3, whichnormally is connected to one side of the phonograph pick-'up as may beseen by reference to Fig. 5. The actuation of the switch blade ||3 alsopermits the switch blade ||4 to be actuated thereby closing a pair ofcontacts ||5 which contacts are connected to control the energization ofa suitable signal light ||6 from a source of power ||1,

Referring more particularly to Fig. 5, it will be seen that thesubscriber play indicator 68 is represented by a dotted rectangleenclosing the magnet coil |02, and the shaft stud H2, the switch bladeH3, the switch blade ||4 and the switch contact 5. The switch blade |3is cone nected to the juncture point between the phonograph pick-up 85,and the resistor 86 and the capacitor 81. The stud ||2 of the shaft |05is normally at ground potential so that whenever the stud ||2 engagesthe switch blade ||3 the output of the phonograph pick-up 85 iseffectively shunted and hence is rendered ineffective. The switch blade|4 and the switch contact ||5 are connected through the signal lamp I6to the source of power |1. The source of power ||1 is further connectedto a signal lamp ||8 controlled by a pair of normally open contacts I9arranged to be actuated in accordance with the movement of thephonograph pick-up arm B5. The phonograph motor 84 is arranged to beenergized from a source of power |2| by means of a pair of contacts |22which are also arranged to be closed upon movement of the phonographpick-up arm 85 from a position of rest with respect to the phonographturntable. The phonograph pick-up 85 -is furthermore arranged to bemaintained in ineffective condition by a pair of contacts |23 which areconnected between ground and the common juncture between the phonographpickup 85 and the resistor 86 and the capacitor 81. These contacts |23are actuated by suitable means responsive to the movement of thephonograph pick-up from a position of rest, and as will subsequentlybecome apparent, will furthermore be actuated whenever the phonographpick-up reaches the end of a phonograph record.

By referring to Figs. 1 to 5 the operation of the system will now becomeapparent by reference to the following description. Whenever asubscriber inserts a coin or coins in the coin-operated switch 3| acircuit is vcompleted through a relay 49 and a capacitor 48 therebycausing the relay 49 to operate. The capacitor 48 has previously beencharged by unidirectional current supplied from a suitable source suchas the half wave rectifier 41 and the alternating current transformer33. In order that the relay coil 49 might not be affected by half-waveor uni-directional current impulses being supplied by the rectifier 41,the relay coil 49 is provided with a nonferrous element such as a copperdisk or ring The surge of current supplied by the capacitor 48 is suchas to produce a very strong initial pull upon the magnet coil 49 so asto insure positive operation of the relay contacts 53 and 54 therebyinsuring transmission of an alternating current impulse over thetelephone line 42 to the coin impulse detector circuit comprising thecapacitor 62 and the connected rectifier elements 63 and 64. During thetransmission of these alternating current impulses the relay 50 openedthe switch contacts 38 thereby insuring that no alternating currentaffected the remainder of the apparatus. The coin detector circuit,responding to the alternating current impulse received at the centralstation over the'telephone line 42 from the subscriber, closes thecontacts 86 actuated by the relay coil or magnet 65 thereby supplyingenergy from a source 61 to actuate the magnet coil |09 of the subscriberplay indicator. Since the initial impulse received by the detectorcircuit removes the stud H2 of the shaft |85 from engagement with theswitch blade 3 thereby permitting the switch blade 4 to engage thecontact H5, the signal light |6 becomes lighted calling the attention ofthe operator. The operator then throws the talk-listen switch 69 rto theright thereby closing a circuit from the microphone 82, the amplifier8|, the switch contacts 18 and 19 through the resistor 94 and the vacuumtube 83, the output transformer 14 thereof, the contacts 1|, 12 of theright-hand portion of the talk-listen switch, the isolating capacitor 13and the isolating transformer 6| to the telephone line 42. The operatorthereupon inquires as to what phonograph record or records are desired.The operators voice currents are transmitted over the telephone line 42to the subscriber station through the transformer 4|, the contacts 39and 46, the contact 38 through a portion of the secondary winding of thetransformer 31, the attenuator 59, the transformer 58 through resistors24 and 25, and the amplifier 26 to actuate the sound reproducer 21. Thesubscriber thereupon, by means of the microphone 35, the amplier 36, thetransformer 31, the balancing network comprising the elements 43 to 45,the switch contacts 38, 39 and 46, the transformer 4| and the telephoneline 42 communicates with the central station operator. The voicecurrents received from the subscriber station over the telephone line 42at the central station are transmitted through the transformer 6|, theisolating capacitor 13, the switch blades at the left of the talk-listenswitch 69, which by this time have been connected with the contacts 15and 16 leading to the head-set 11 of the central station operator. Y

The central station operator, having made a record of the phonographrecords desired, selects them from the phonograph magazine or library|02 and places them in the phonograph record recess |91 corresponding tothat particular subscriber. One of these records is thereupon placed onthe turntable 84, and the phonograph pick-up is removed from theposition of rest to the beginning of a phonograph record. The phonographrecord actuates the stylus of a phonograph pick-up 85 which is connectedthrough a suitable network comprising the resistor and capacitorelements 86, 81, 88, 89 and 9|, the amplifier 83, the transformer 14,the switch contacts 1| and 12, the isolating capacitor 13, and thetransformer 6|, to the 'telephone line 42. At the subscriber station thetelephone line 42 is connected through the transformer 4| to thecontacts 39 and 46 which in turn are connected through the contacts 38through a portion of the transformer 31, the attenuator 59, thetransformer 58, the resistors 24 and 25, the amplifier 26, to the soundreproducer 21. Whenever the phonograph record has been completed, theswitch contacts I I9 of Fig. 5 are closed thereby energizing the signallight ||8 indicating to the centrall station operator that the nextrecord is to be played. When all of the records selected by thesubscriber have been played, the indicator dial |03 of the subscriberplay indicator 68 is returned to zero by the central station operatorwho rotates the shaft |85 by means of a suitable knob secured thereto.

By reference to Figs. 6, '1 and 8, it will be seen how the phonographpick-up 35 is provided with means responsive to its movement forcontrolling the operation of such switches as the signal switch ||9, themotor control switch |22, and the phonograph pick-up switch |23. Thephonograph pick-up 85`is supported upon a member |25 which is secured toa shaft |26 mounted within suitable supporting means |21. `Thesupporting means |21 is secured to a panel' or base |28 which in turnsupports numerous other elements including the phonograph turntable 8'4.The shaft |26. extends through the supporting housing |21 to somedistance beneath the panel or mounting plate |28. A pair of actuatingmembers or armsr |29 and |3I are arranged to be adjustable with respectto each other and with respect to the shaft |26. These actuating members|29 and |3| may be secured in position with respect to each other bymeans of a suitable bolt and slot arrangement |32, and may be secured inposition with respect to the shaft |26 by means of a suitable lockingcollar |33. The switch |22 which controls the operation of thephonograph turntable motor is of the spring-biased type which normallyis in closed position, and hence the switch is provided with anoperating arm |34 by means of which this bias is overcome so as to openthe circuit of the switch |22. In the parked position of the pick-up'85the actuating arm |29 secured thereto is in contact with the switch arm|34 of the electric switch |22 thereby opening the circuit of theswitch. As soon as the phonograph pick-up 85 is moved from its parkedposition to the edge of a phonograph record, the switch 22 is closed andthe phonograph turntable motor is energized.

In Fig. 5 there was shown a pair of switches ||9 and |23 which wereoperatedA in response to movement of the phonograph pick-up 85'. In thearrangement shown in' 'Fig'." 6 'the' switch V| I9 is biased so as nto@be normallyoperi circuit. The switch |23 is shown Vas comprising asingle switchblade which is connected to the juncture betwen`tl'iev"phonograph pick-up 85 and the inputfjo'f `'the phonograph pick-upamplier. VYAn 'ovr-centerbiased switch operating member |35 is'normallyat ground potential,A andwhenever this operating member engages the'switch' blade |23,-"th e phonograph pick-up isn rendered ineffective.

The 'over-center 'actuating member |35 is springbiased by means of asuitable spring' |35 Aand is provided Ywith a' pair of operatingportions |`31`fand"|38fa`djacent one extremity thereof. 'I'he other'extremity |39 of the actuating membe'ris 'arranged toV engage the.switch blade |2351 Thezoperatingi members |31 and |38 are arranged toVbeje'ngaged with the extremity of a phonograph pick-up operating lever|3| at a time whenlthe phonograph pick-up 85 has left the L end'of. `thephonograph reco-rd. This po- Ysition'ofthe operating' elements .is shownin Fig; '7' since the extremity of the member has engaged the operatingportion |31 of the overcentertswitch actuating means |35. When thecentraltistation operator returnsrv the phonograph. pick-up 85 to theparked position, the extremity1of-the, operating member |3| will engagethe'actuating portion |38 ofthe over-center switch actuating member |35thereby restoring theswitchto the position shown Vin Fig. 6. In orderfthat the operation of the switch vactuating means |35 might ibear theproper relation to the position of the phonograph pick-up 85 relative toa phonograph record on the turntable vt4, the actuating member |35 issupported from a spring biased bell-'crank support |4| which, yat,Y oneextremity is provided with an adjustment set screw 42 bearing against aportion of the mounting plate |28. Thus, it is possible by utilizingthis adjustment of the switch actuating means |35 andthe adjustableportions of the switch actuating arms |29 and |3| relative to each otherand relative to the phonograph pick-,up 85 to produce the properoperation of each of the switches in accordance with the phonographpick-up 85 relative to the phonograph vturntable 8'4.

In order to conveniently retain the phonograph pick-up 85 in a parkedposition, there may be provided, as shown in Fig.V 9, a spring-biasedlatch arrangement supported from the mounting plate kor panel |28 bymeans of a member |43 which supports a structure |44 upon which there isprovided a catch |45 which is suitably biased by a spring |46. The catch|45 engages the under side of the channel portion of the phonographpick-up arm 85 whenever the arm is returned to parked position. In orderto remove the arm from this position, the pick-up is raised sufficientlyto permit the arm to clear the catch portion of the member |45.

Another arrangement of operating means and switch members is shown inFigs. to 16. In the arrangement herein shown, switches have been giventhe Vsame reference characters as were yapplied in previous disclosures.The phonograph turntable motor switch |22 is of the same type asutilized in the previous embodiment and is provided with an operatingmember |34. The phonograph pick-up 85 mounted upon the shaft |26 isprovided in this instance with a single switch arm |41 adjustablysecured to the Vshaft"|2t"l`)y'a'ny convenient means such as alsetis'crew |48." The switches ||9 and |23 and theunotorswitch' |22 areactuated by a switch actuatingmember |49 which is supported from asuitable' Vstud /member |5| which may be 'mountedupona plate |52supported above the panel|28. `The switch actuating member |49 is``biased by `aV spring |53 in a direction so as to tend' normally to' openthe motor switch |22 and'toic'lose'the switches |23 and H9. It willbenot'ed thatthe switch v'actuating member |49 inthe present arrangementis to be maintained at ground potential so as to cooperate with theVswitch blade |23 inlthe'same manneras would lthe, switchactuatingniember |35 'shown in Fig; 6. 11 1i .i

In Fig.-l 2 there is Yshown a catch |54 suitably biased by a spring|55'and supported from a memberA |55 which in turn is mounted upon athreadedjmember Y|51 supported by suitable posts such as |58 which maybe a portion of the mounting member |52. This arrangement permits.Yacertain latitude of adjustment of the position of the catch |54. Byreferring to Fig. 13V it will be seen that the catch |54 is engaged |48when the phonographgpick-up 85 is in a position of rest. At the sametime the arm |41 mounted on the phonograph pick-up is in engagement withthe arm portion |6| of the switchactuating member |49 so that thislatter member is biasing the switch |22 to open circuit position.`

When the phonograph pick-up 85 is moved but a short distance fromits'parked position or position of rest as indicated by the small angleA, theiarm |41 has been moved sufficiently to permit Vjthe spring-biasedswitch actuating member |49 to follow the movement of the arm |41sufficiently to disengage the arm portion ISI from the switch arm |34 ofthe switch |22, thereby starting ftheY phonograph turn-table. At thesame time Ythe lever portion |59 of the switch actuating member |49 hasbeen moved so that ,itl no longer engages the catch |54.

YAs the phonograph pick-up 85 moves across the phonograph record, thearm |41 continues to 'move in a counter-clockwise direction as may beseenfrom Fig; l5, and the spring-biased switch actuating member |49continues to follow until the lever |59 thereof engages the forwardportionof the catch |54. Further movement of the phonograph pick-up arm85 from the solid linefposition shown in Fig. 15 up to the dotted lineposition produces no further movement of the switch actuating member|49. When the phonograph record has been completely reproduced and thestylus of the phonograph pick-up 85' has entered the shut-off or cut-offgroove on the phonograph record, the armA will be moved through a smallangle indicated at B in Fig. 16. At this time the arm |41 of thephonograph pick-up 85 engages a releaseportion |62 of the catch |54thereby freeing the arm portion |59 of theV spring biased switchoperating member |49 so that the arm |59 engages the switch blade |23thereby rendering ineffective the phonograph pick-up 85. At the sametime the switch contacts H9V are closed thereby closing a circuit to asignal lamp such as ||8 to inform the operator that the record has beenreproduced. Simultaneoursly with the engagement of the switch arm |59with the switch blade |23, a switch cam portion |63 on the operatingmember |49 engages the outer extremity of the switch arm |34 of themotor switch |22 thereby opening this switch to stop the phonographturntable motor. When the central station operator lifts the phonographpick-up 85 from the record and returns it to a position of rest, theswitches are again returned to the position shown in Fig. 13.

In Fig. 17 there is shown the application of the present invention to asystem more generally referred to as a double channel system wherein onetelephone line is utilized to transmit coinoperated impulses to thecentral station and to transmit voice currents to the central station.Another channel is used exclusively for the transmission of phonographrecord currents from the central station to the subscriber station. Forsimplicity in disclosure and understanding of the present system, thoseportions of the circuit which are similar to the elements previouslydisclosed in connection with the single channel system of Fig. 1 havebeen given similar reference characters. In the arrangement shown inFig. 1'1 there is provided a plurality of rectiiier elements 41 and atransformer 33 comprising a source of uni-directional current having arelatively high impedance, or in other words, a limited current outputcharacteristic, which is utilized to charge a capacitor 48. Analternating current relay switch |66 is connected so as to be energizedby the capacitor 48 by means of the coin-operated switch 3|. Amicrophone 35 connected through a suitable amplifier 36 is normallyconnected by means of the switch contacts |61 and |68 to a telephoneline |69 by means of a transformer |1|. The operation of the relay |66is such as to open the contacts |61 and |68 thereby dis-connecting theamplifier from the telephone line and to close the contacts |12 and |13thereby connecting through suitable alternating current filter means|14, |15 alternating current potential tot the transformer |1I, whichpotential is obtained from a suitable transformer |16 which may beconnected to the alternating current source 34. Thus, whenever thecoinoperated switch 3| is actuated, the relay |66 serves to transmitalternating current impulses to the central station. These alternatingcurrent impulses are received at the central station by an impulsedetector circuit comprising the capacitor 62 and the reversely connectedrectiers 63 and 64. These elements, which have been calledl a coinimpulse detector circuit, are connected to control the relay 65 whichwhen operated closes the contacts 66 which are connected in series withthe source of potential 61 thereby to actuate a subscriber playindicator 68. The input to the detector circuit may comprise thesecondary winding of a suitable transformer |11 connected to thetelephone line |68. Whenever the operator has been signaled by thesubscriber play indicator 68, a talk-listen switch |18 is actuated so asto `connect the microphone 82 and its amplifier 8|, by means of theswitch contacts |19 and ISI, to the cathode and through a resistor |82to the control grid respectively of an amplifier tube |83. The amplifiertube |83 may be connected through suitable isolating transformers |84and |85 to a telephone line |36 which is connected with a subscriberstation. At the subscriber station the telephone line |86 may beconnected through a suitable transformer |81 to an attenuator 59 whichin turn is connected through a transformer 58 by means of a switch 26 tothe input of the amplier 26 which operates the sound reproducer 21. Uponinquiring as to what selection the subscriber desires, the centralstation operator, havinglactuated the switch |18 thereby closed thecontacts |88 and |89 so aspto connect the ,headphone 11 to thetransformer 11 which in turn is connected to the telephone line |66.Upon receiving instructions from the subscribenvthe switch |18 isreturned to normal positionand a phonograph record is placed upon theturntable 84 which is reproduced by the phonograph pick-up 85 which isconnected to an input circuit comprising capacitors IBI, |92 and |93 andresistors |94 and |95 which are connected to the input of the amplifiertube |83. While the present arrangement has shown the equipment of onlyone subscriber, it, of course, is to be understood that any number ofsimilar units may be utilized depending upon the number of subscribersto the central station. v

While we have shown our invention as applied to certain specicembodiments, it is to be understood that we do not wish to be limitedthereto since it will be apparent that numerous changes may be made inthe circuit arrangements and in the instruments employed withoutdeparting from the spirit andv scope of the invention as set forthvinthe appended claims.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In a phonograph system for electrically reproducing phonographrecords including a central station and a plurality of subscribersstations connected thereto by telephone lines, means located at eachsubscriber station for transmitting a current impulse to said centralstation, said means including a source of low frequency pulsatingcurrent,'an alternating current relay for connecting said source to saidtelephone line, a circuit for energizing said relay comprising a sourceof uni-directional current, a capacitor and a switch, said capacitorbeing connected in series with said relay and said switch, and saidunidirectional current source being connected to charge said capacitorwhereby said relay will be operated by current from said capacitor toinsure positive operation of said relay.

2. In a phonograph system for electrically reproducing phonographrecords including a central station and a plurality of subscribersstations connected thereto by telephone lines, means located at eachsubscriber station for transmitting a current impulse to said centralstation, said vmeans including a source of alternating current connectedto a transformer having a low regulation characteristic, a rectierconnected toY said transformer, a capacitor'connectedV to be charged bysaid rectier, a source of pulsating current, an alternating currentrelay for connecting said latter source to said telephone line, and aselectively operable switch connected in series Vwith said relay andsaid capacitor whereby said relay may be operated positively byfcurrentsupplied by said capacitor. v

3. Inv a phonograph system for electrically reproducing phonographrecords including a 4central station and afplurality of subscribersstations connected Ythereto by telephone lines, coincontrolled meanslocated at each subscriber stationl fortransmitting current impulses tosaid central station in accordance with the value of the Ycoins receivedthereby comprisingv a source of alternating current connected to ahighimpedance transformer, a rectier connected to said transformer, acapacitor connected to be charged by said rectier, a source ofY lowfrequency alternating current,Y alternating Ycurrent filter meanstherefor, an alternatingcurrent vrelay for connecting said lattersource-to said telephone line through-said filter means, and acoincontrolled switch connectedin series with said relay and saidcapacitor whereby said relay will be operated positivelyV byYcurrent'supplied` by said capacitor. Y j Y 4. In a phonograph system forelectrically reproducing phonograph records 'including ay centralstation and a plurality of subscribers stations connected thereto bytelephone lines, means located at each subscriber station includl ingcommunication apparatus normally connected to said central station byone`of said telephone lines, coin-controlled means for transmitting tosaid central station current impulses in accordance with the value ofcoins received thereby, said means including a source of low frequencyalternating current, alternating4 current V'filter means, a relay switchfor disconnecting said telephone line from said apparatus and forconnecting said telephone line'to said source of alternating currentVthrough said filter means, anda relay operated in response to currentflowing from said alternating current source to said telephone line fordisconnecting `said apparatus'from said relay switch;

5. In a phonograph system for electrically reproducing phonographrecords including a` central station and a plurality of subscribers staftions connected thereto by telephone lines, means located at eachsubs'criber'station including communication apparatus for communicatingVwith said central station and for reproducing sound, said apparatusbeing normally connected with said central station by one of saidtelephone lines, coin-controlled' means for transmitting Yto saidcentral station current impulses in accordance with the value of coinsreceived thereby, said means including a source of low frequencyalternating current, alternating current filter means therefor, a relay'switch for disconnecting said telephone line vfrom said apparatus andfor connecting said telephone line to said source'of alternating currentthrough said lter means, a circuit for energizing the relay of saidswitch in accordance with the value of coins received by saidcoin-controlled means including a switch operated thereby, a capacitorconnected in series with said relay of said switch and with said latterswitch, a source of uni-directional current for charging said capacitor,and a relay operated in response to current flowing from saidalternating current source to said telephone line for disconnecting saidapparatus from said relay switch,

6. In a phonograph system for electrically reproducing phonographrecords including a central station and a plurality of subscribersstations connected thereto, coin-controlled means located in eachsubscriber station for transmitting alternating current impulses tosaidcentral station in accordance with the value of coins receivedA thereby,a circuit located at said central station for receiving said currentimpulses including a capacitor and a rectifier connected across theinput of said circuit, a second rectifier reversely connected withrespect to said rst rectifier and an output circuit connected betweenthe remaining terminal of said second rectifier and the juncture betweensaid first rectifier and said capacitor. Y

7. In a phonograph system for electrically reproducing phonographrecords including a central station and a plurality of subscribersstaitions connected thereto, coin-controlled-means 75 Ylocatedateach-subscriber station for transmitting alternating current impulses tosaid central station in accordance with the value of coins Yreceivedthereby, a circuit located at said central station for receiving saidalternating current impulses including-a capacitor and a rectifierconnected across the input 4of said circuit, a second rectifierreversely connected with respect to said first rectifier, an outputcircuit connected between the remaining terminal of said secondrectifier andthe juncture of said first rectifier and said capacitor,and means connected across said output circuit for indicating the valueof coins received by said coin-controlled means at said subscriberstation.

8. In a system for electrically 4reproducing phonograph records, thelcombination with a telephone circuit comprising means for transmittingover said circuit electrical currents of varying frequencycorresponding' to sound undulations; an impulse switch locatedat one endof said telephone cir-cuit and adapted when momentarily closed todeliver to saidY telephone circuit an alternating current of higher'potential than said first currents; and'indicating means connected tothe other vend of said telephone circuits to receive rboth. saidelectrical currents corresponding to sound undulations'an'd said higherpotential alternating current, said indicating means beingdifferentially actuatable by said alternating current of higherpotential.

9. In a phonograph system for electrically reproducing phonographrecords, including a central station and a plurality of subscribersstations connected thereto, phonograph reproducing apparatus comprisingcertain elements located at said central station and certain elementslocated at each subscriber station, coin-'controlled means located ateach subscriber station for transmitting alternating current impulses tosaid central station in accordance with the Value of coins receivedthereby, a Icircuit located at said central station for receivingsaidcurrent impulses including a capacitor and a rectifier seriallyconnected across the input of said circuit, a second rectifier reverselyconnected with respect to said first rectifier, an output circuitconnected between the remaining terminal of said second rectier and thejuncture between said first rectifier and said capacitor, and meansconnected across said output circuit for controlling the effectivenessof at least one of the phonograph reproducing elements located at saidcentral station.

l0. A system for electrically reproducing phonograph records comprisinga central station and a plurality ofsubscribers stations each connectedthereto by a telephone circuit, a coin-operated switch located at eachsubscriber station, means responsive to actuation of said switch fortransmitting to said central station an alternating current impulse of acertain voltage, means normally connected to one end of said telephoneline for transmitting a voice communication from said subscriber stationto said -central station, means normally connected to said end of saidtelephone circuit for reproducing electrical energy corresponding Atosound undulations received from said central station, means responsiveto operation of said coin switch for disconnecting said latter two meansfrom said telephone line during the transmission of said alternatingycurrent impulses, means for each subscriber located at said centralstation for receiving and indicating said alternating current impulsesfrom said subscriber station, means for each subscriber normallyconnected to the central station end of said telephone lcircuit fortransmitting to said subscriber station currents corresponding tophonograph records, and means selectively connectible to said end ofsaid telephone circuit for voice communication with said subscriberstation.

11. A system for electrically reproducing phonograph records comprisinga central station and a plurality of subscribersl stations eachconnected thereto by a two wire telephone line, a coin-operated switchlocated at each subscriber station, means responsive to actuation ofsaid switch for transmitting to said central station an alternatingcurrent impulse of a certain voltage, means normally connected to theend of said telephone line for transmitting a voice communication tosaid central station, means normally connected to said end of saidtelephone line for reproducing electrical renergy corresponding to soundundulations received from said central station, means responsive tooperation of said coin switch for disconnecting said latter two meansfrom said telephone line during the transmission of said alternatingcurrent impulses, means for each subscriber located at said centralstation for receiving and indicating said alternating current impulsesreceived from said subscriber station, said means being responsive tovoltage eX- ceeding a predetermined amount, means for each subscribernormally connected to said telephone line for transmitting to saidsubscriber station currents corresponding to phonograph recordundulations, and means selectively Iconnectible to said telephone linefor voice communication with said subscriber station.

l2. A system for electrically reproducing phonograph records comprisinga central station and a plurality oi subscribers stations eachyconnected thereto by a double channel telephone circuit, acoin-operated switch located at each subscriber station, means normallyconnected at said subscriber station to one channel of said circuit fortransmitting a Voice communication to said central station, meansresponsive to actuation of said ceiving and indicating said alternatingcurrent impulses, means for each subscriber normally connected at thecentral station to one channel for transmitting to said subscriberstation currents corresponding to phonograph record undulations, andmeans selectively connectible to the other of said channels for voicelcommunication with said subscriber station.

13. In a remote control phonogra-ph record playing system of thecharacter described for transmitting sound over a plurality of fourconductor telephone circuits, the combination of t a plurality ofseparate location stations; means for operatively connecting each ofsaid location stations to one end of a corresponding one of saidtelephone circuits; a central control station at the `other end of saidtelephone circuits; a sound reproducing means, and means for connectinga microphone and said sound reproducing means selectively to saidtelephone circuits; a coin-operated switch at each location station fortransmittingan electrical impulse `of a predetermined voltage value overthe circuit associated with this said station; an indicating means atsaid control station for each of said circuits responsive to voltageabove a predetermined value for indicating the number of actuations ofsaid coinactuated switch by current ilowing over the correspondingtelephone circuit; and a plurality of record playing means at saidcentral station corresponding in number to said location stations andrespectively associated with them for transmitting over any particular-circuit a number of records corresponding to the number of impulsesreceived by said indicating means.

14. In a phonograph record playing system of the character described foruse with a telephone circuit, the combination of; means connected to oneend of said circuit at a subscribers station for translating waves ofvarying frequency from an electrical conductor medium to an air medium,and an air medium to an electrical conductor medium; means at saidsubscribers station for impressing on said one end of said circuitelectrical impulses of a denite frequency and Voltage; means at acentral station at the other end of said circuit for translating wavesof varying frequency from an electrical conductor medium to an airmedium and from an air medium to an electrical conductor medium, meansat said central station for diierentially receiving and indicating saidelectric impulses of denite frequency and voltage; and means forreproducing a sound record at said :central station, said means beingconnected to said other end of said circuit.

15. A system for electrically reproducing phonograph records comprisinga central station and a plurality of subscribers stations each connectedthereto by a telephone line, a coin-operated switch located at eachsubscriber station, means normally connected to said telephone line atsaid subscriber station for receiving and for transmitting undulationscorresponding to sound, means responsive to actuation of said switch fordisconnecting said latter means and for transmitting to said centralstation an alternating current impulse of a certain voltage, means foreach subscriber normally connected at the central station to saidtelephone line for transmitting to said subscriber station currentscorresponding to sound undulations, and means connected to said end ofsaid telephone line for receiving and indicating altternating currentimpulses received from said subscriber station, said means beingquantitatively responsive to alternating current voltage impulses havinga predetermined value.

16. The combination in a system of electrically reproducing phonographrecords comprising a central station, a plurality of subscribersstations each connected thereto by a telephone line, means for eachsubscriber for reproducing the phonograph records, certain elementsthereof being located at said subscriber station and other elementsthereof being located at said central station, said latter elementsincluding a phonograph pick-up and an amplifier therefor, and amicrophone for communicating with said subscriber station, said amplierincluding a vacuum tube having a cathode resistor, a resistor adapted tobe connected across the input ofsaid amplifier, a selectively operableswitch interconnecting said microphone, said resistor and Vsaid cathoderesistor of said amplifier, and circuit connections whereby said switchupon operation will connect said resistor across the input of saidamplifier and simultaneously connect the output of said microphoneacross said cathode resistor.

1'7. The combination in a system of electrically reproducing phonographrecords comprising a central station, a plurality of subscribersstations each connected thereto by a telephone line, means for eachsubscriber for reproducing the phonograph records, certain elementsthereof being located at said subscriber station and otherv elementsthereof being located at said central station, said latter elementsincluding a phonograph pick-up and an amplifier therefor, and means forcommunicating with said subscriber station, said means being selectivelyconnectible to said latter elements whereby simultaneously voicecurrents and phonograph sound currents may be transmitted, said meansincluding a resistor connected across the input of said amplifier forreducing the magnitude of the phonograph sound currents to betransmitted.

18. The combination in a system for electrically reproducing phonographrecords comprising a central Station, a plurality of subscribersstations each connected thereto by a telephone line, means for eachsubscriber having reproducing phonograph records, certain elementsthereof being located at said central station and. including aphonograph pick-up and an amplifier therefor,means for communicatingwith said subscriber station including a microphone, and means includinga switch Aconnected between said microphone and said amplier so as toreduce the amplication 'of energy from said phonograph pick-up by apredetermined amount whenever said microphone is connected to 'saidamplier. Y Y

19. The combination in a system for electrical'- ly reproducingphonograph records comprising a central station, a plurality ofsubscribers stations each connected thereto by a telephone line, meansfor each subscriber for reproducing phonograph records, certain elementsthereof being located at said subscriber station and other elementsthereof being located at said central station, said latter lementsincluding a phonograph pick-up and an amplifier therefor, and aplurality of networks connected between said pickup and said amplifier,each network operating over a different frequency range for compensatingfor the attenuation at frequencies in that range occurring inthetransmission to said subscriber station of currents corresponding tosound undulations of 'a phonograph record.

20. The combination h'avi'ng'a system for electrically reproducingphonograph records cornprising a central station and Yat least onesubscriber stationconnected thereto Vby a telephone line, means for eachsubscriber lfoi` reproducing phonograph records, certain elementsthereof being located at said subscriber station and other elementsthereof being located "at said central station, and means located atsaid subscriber station for 4communicating with said central station,said Vmeans and lsaid firstl elements being interconnected with Veachother and said telephone line by a bridge circuit including means forbalancing said circuit thereby to pre- Vent feedback.

21. In a phonograph Vsystem for electrically reproducing phonographrecords comprising a central station and a plurality of subscribersstations connected therto, means for each subscriber for electricallyreproducing phonograph records, certain elements thereof being locatedVagencer nograph turntable motor and a pick-up, a switch biased to closedposition for controlling the operation of said motor, a snap action'switch normally open for controlling the effectiveness of another ofsaid elements, means operated by the movement of said pick-up foractuating said switches, ,said means having a period of free travelbetween said switches during the reproduction of a phonograph record,said means further operating at the end of a phonograph record to closesaid snap action switch.

22. In a phonograph system for electrically reproducing phonographrecords comprising a central station and a plurality of subscribersstations connected thereto, means for each subscriber for electricallyreproducing phonograph records comprising certain elements located atsaid central station and other elements located at each subscriberstation, said elements at said central station including a phonographturntable mo'tor and a pick-up, a switch biased to closed position forcontrolling the operation of said motor, a signal device, a snap actionswitch biased to open position for controlling the effectiveness ofanother of said elements-and to energize said signal device, meansoperated by the movement of said pick-up for actuating said switches,said means operating to permit said first switch to be closed uponmovement of said pick-up from a f, position of rest and to actuate saidsnap action Vcentral station including a phonograph turntable motor andpick-up, a switch biased to closed po'- sition for controlling theoperation of said motor, a snap action switch biased to open positionfor controlling the effectiveness of another of said elements, meansoperated by the movement of said pickup for actuating said switches,said means operating to permit said rst switch to be closed Y andsaidvsnap action switch to be opened upon movement of said pickiup froma position of rest to the beginning of a phonograph record.

In 'a phonograph system for electrically reproducing phonographrecordscmprising a cenc tral station and a plurality of subscribersstations c'onnectedjthereto, means for 'each subscriber forVelectrically reproducing phonograph records, certain elements thereofbeing located at said central station and 'other elements thereof beinglocated at said subscriber station, said elements at s aid centralstation including a phonograph turntable motor and 'a phonograph pickup,'a switch biased to closed position 'for controlling said motor, `Vasecond switch biased to open position for controlling the effectivenessof anotherof s'aid elements at s'aid central station, means operable bythe movement of said phonograph pick-up for actuating saidswitches, saidmeans comprising an arm mounted 'on said phoncgraph pick-up, a switchactuating member cooperating with said arm, said member being biased ina direction tending 'to close said second switch, said member having amotor (switch operating arm, a motor .switch cam 'surface and a switchlever for said second switch, a catch biased to engage said latterswitch lever vwith said second switch, said catch being provided with arelease surface arranged to be engaged by said arm upon completion ofthe playing of a phonograph record, thereby to provide a snap actionoperation of said second switch and of said motor switch, said camsurface of said actuating means engaging said motor switch concomitantlywith the engagement of said lever with said second switch.

25. In a phonograph system for electrically reproducing phonographrecords comprising a central station and a plurality of subscribersstations connected thereto, means for each subscriber for electricallyreproducing phonograph records, comprising certain elements located atsaid central station and other elements located at said subscriberstation, said elements at said central station including a phonographturntable motor, a phonograph pick-up, a switch biased to closedposition for controlling the operation of said motor, a second switchbiased to open position for controlling the effectiveness of saidphonograph pick-up, and means operable by the movement of said pick-upfor actuating said switches, said means comprising an arm adjustablymounted with respect to and on said phonograph pick-up, a switchactuating member cooperating with said arm, said member being biased ina direction tending to close said second switch, said member having amotor switch actuating arm, a motor switch cam surface and a switchlever for said second switch, a catch adjustably mounted with respect tosaid latter lever and biased to engage said latter lever to delay theengagement of said lever with said second switch, said catch being f'provided with a release surface arranged to be engaged by said arm uponcompletion of the reproduction of a phonograph record, thereby toprovide a snap action operation of said switches,

said cam surface of said actuating member engaging said motor switchconcomitantly with the engagement of said lever with said second switch.

26. In a phonograph system for electrically reproducing phonographrecords comprising a central station and a plurality of subscribersstations connected thereto, means ior each subscriber for electricallyreproducing phonograph records, certain elements thereof being locatedat said central station and including a phonograph turntable motor, aphonograph pick-up, a switch biased to closed position for controllingthe operation of said motor, a second switch biased to open position forcontrolling the effectiveness of one of the elements at said centralstation, said switch being provided with an over-center biased actuatingmember whereby to provide a snap action operation, and means operable bythe movement of said pick-up for actuating said switches, said meanscomprising a pair of arms mounted on said pick-up in adjustable relationto each other and to said pick-up.

27. In a phonograph system for electrically reproducing phonographrecords comprising a central station and a plurality of subscribersstations connected thereto, means for each subscriber for electricallyreproducing phonograph records comprising certain elements located atsaid central station and other elements located at said subscriberstation, said elements at said central station including a phonographturntable motor, a phonograph pick-up, a switch biased to closedposition for controlling said phonograph motor, a second switch biasedto open position to render effective another of said elements at saidcentral station, said switch being provided with an over-center biasedactuating member whereby to provide a snap action operation, and meansoperable by the movement of said pick-up for actuating said switches,said means comprising a pair of arms mounted on said phonograph pick-upin adjustable relation to each other and to said pick-up, said meansoperating to close said motor switch and to open said second switchwhenever said pick-up is moved from a position of rest with respect tosaid turntable.

EUGENE L. TRIMAN. LAWRENCE E. DE'ITLE.

